Abstract: In order to realize the portable and digital crop production management, based on the theory of precision agriculture and the precision crop management model, a Pocket PC-based portable precision farming system (PPFS) was developed by integrating Pocket PC, embedded-GIS, SQL Server CE and GPS, using the thought of system engineering and software component technology. The system realized the functions such as map handling, information management, cultural plans design, fertilizer and water management ect, suitable growth indices design, real-time regulations based on the crop growth status, and system help. In 2007-2008, the demonstration and application of PPFS were carried out in Jiangsu, Zhejiang and Henan provinces. The results in field experiments indicated that the system could design suitable crop precision management schemes according to field factual status, the average rice yield with precision management plans was 10435.3 kg/hm2 with increasing rate being 12.83%; Based on precision management plans, the wheat yield rose by 9.02% with an average yield of 8124.6 kg/hm2 and the amount of nitrogen fertilizer reduced. The present work provides a new service platform and application pattern for precision farming management.